Yes, you can add navigation to the factory system. Here is one company that makes it.
http://www.mocar.us/navigation-oe-in...vy-gmc/camaro/
When I looked into it 6 months ago it was around $1500 for the full install. I didn't look hard for a way to buy it without paying someone to install it.
It has been discussed on the forum before and some people have had it done.